diff --git a/Network/Wai/Handler/Warp.hs b/Network/Wai/Handler/Warp.hs
--- a/Network/Wai/Handler/Warp.hs
+++ b/Network/Wai/Handler/Warp.hs
@@ -31,6 +31,7 @@
   , settingsTimeout
   , settingsIntercept
   , settingsManager
+  , settingsFdCacheDuration
     -- ** Data types
   , HostPreference (..)
     -- * Connection
diff --git a/Network/Wai/Handler/Warp/FdCache.hs b/Network/Wai/Handler/Warp/FdCache.hs
--- a/Network/Wai/Handler/Warp/FdCache.hs
+++ b/Network/Wai/Handler/Warp/FdCache.hs
@@ -76,8 +76,8 @@
 
 ----------------------------------------------------------------
 
-initialize :: IO MutableFdCache
-initialize = do
+initialize :: Int -> IO MutableFdCache
+initialize duration = do
     mfc <- newMutableFdCache
     void . forkIO $ loop mfc
     return mfc
@@ -86,7 +86,7 @@
         old <- swapWithNew mfc
         new <- pruneWith old prune
         update mfc (merge new)
-        threadDelay 10000000 -- FIXME
+        threadDelay duration
         loop mfc
 
 prune :: t -> Some FdEntry -> IO [(t, Some FdEntry)]
diff --git a/Network/Wai/Handler/Warp/Run.hs b/Network/Wai/Handler/Warp/Run.hs
--- a/Network/Wai/Handler/Warp/Run.hs
+++ b/Network/Wai/Handler/Warp/Run.hs
@@ -126,7 +126,7 @@
     tm <- maybe (T.initialize $ settingsTimeout set * 1000000) return
         $ settingsManager set
 #if !WINDOWS
-    fc <- F.initialize
+    fc <- F.initialize (settingsFdCacheDuration set * 1000000)
 #endif
     mask $ \restore -> forever $ do
         allowInterrupt
diff --git a/Network/Wai/Handler/Warp/Settings.hs b/Network/Wai/Handler/Warp/Settings.hs
--- a/Network/Wai/Handler/Warp/Settings.hs
+++ b/Network/Wai/Handler/Warp/Settings.hs
@@ -25,6 +25,7 @@
     , settingsTimeout :: Int -- ^ Timeout value in seconds. Default value: 30
     , settingsIntercept :: Request -> Maybe (Source (ResourceT IO) S.ByteString -> Connection -> ResourceT IO ())
     , settingsManager :: Maybe Manager -- ^ Use an existing timeout manager instead of spawning a new one. If used, 'settingsTimeout' is ignored. Default is 'Nothing'
+    , settingsFdCacheDuration :: Int -- ^ Cache duratoin time of file descriptors in seconds. Default value: 10
     }
 
 -- | The default settings for the Warp server. See the individual settings for
@@ -44,6 +45,7 @@
     , settingsTimeout = 30
     , settingsIntercept = const Nothing
     , settingsManager = Nothing
+    , settingsFdCacheDuration = 10
     }
   where
     go :: InvalidRequest -> IO ()
diff --git a/warp.cabal b/warp.cabal
--- a/warp.cabal
+++ b/warp.cabal
@@ -1,5 +1,5 @@
 Name:                warp
-Version:             1.3.1.2
+Version:             1.3.2
 Synopsis:            A fast, light-weight web server for WAI applications.
 License:             MIT
 License-file:        LICENSE
@@ -26,7 +26,7 @@
                    , http-types                >= 0.7      && < 0.8
                    , lifted-base               >= 0.1      && < 0.2
                    , network-conduit           >= 0.5      && < 0.6
-                   , simple-sendfile           >= 0.2.4    && < 0.3
+                   , simple-sendfile           >= 0.2.7    && < 0.3
                    , transformers              >= 0.2.2    && < 0.4
                    , unix-compat               >= 0.2
                    , void